"took it" or "has taken it"

"Took" is simple past tense. I took it yesterday. I took the bus yesterday.

"Has taken" is present perfect tense, and describes an act which was performed/completed in the very recent past. I can't find my pen. I think someone has taken it.

Note that with the simple past, the endings don't change with person and number.
I took it.
We took it.

PicnicIn which context should one each of them be used?

Use "took it" when telling a story about what happened in the past. Use "has taken it" when commenting on something you have just noticed in the present.

-- What happened to the key?
-- Jack had to use the car to go somewhere, so he

If i have noticed that something which is mine had been stolen BY someone i know(or think) can i use perfect?

If i have noticed that something which is mine had been stolen BY someone i know(or think) can i use perfect?

I don't exactly follow your sentence, but my answer is "Yes." (I think you just did!)

yes i have meant pressent simple

is my scentence wrong?

dont you need to say: "I think you just have!" ?

PicnicIf i have noticed that something which is mine had been stolen BY someone i know(or think) can i use perfect?

If I notice that something which is mine has been stolen by someone I

IF i want to sa...can i - is it correct?

"It looks like someone [has taken / has stolen] my [key / book / ...] yesterday [or in exact time]."

but why did you change my scentence its right to say "if i have noticed"...and dont forget that there is present perfect in the same scentence...

Picnicwhy did you change my scentence sentence

I made it more idiomatic. I made it just like a native speaker would say it.

Picnic[has taken / has stolen] my [key / book / ...] yesterday [or in exact time]."

No. You can't combine present perfect and an adverb that gives a definite time in the same sentence.

what do yu mean by idiomatic?
but its wrong to say if i have [past]

right?
oh yeah i jsut wanted to make sure

Avangi (I think you just did!) Edit.

dont you need to say: "I think you just have!" ?

There are cases where such a reply would be restricted to a particular tense.

But your question is about a future action: "Can I do X?" (I suppose it could be present/habituation.)